UV–Vis microspectrophotometric study of wool and polyamide fibres dyed with analogous gryfalan dyes

• Wool and polyamide fibres, dyed with analogous metal-complex dyes, were matched.
• The affinity of used dyes to the different type of fibres was assessed.
• The influence of fibre polymer on a quality of obtained UV–Vis spectra was analysed.
• The use of chemometric analysis to discriminate slightly dyed fibres was presented.

The presented study was dedicated to the comparison between wool and polyamide fibres, dyed with metal-complex (gryfalan) dyes being analogous regarding type and concentration, with the use of UV–Vis microspectrophotometry. The affinity of used dyes to the particular fibre type as well as the influence of fibre polymer on the quality of spectra obtained were subjected to evaluation. The absorbance spectra, obtained with the use of a 20/20 PV™ microspectrophotometer (CRAIC Technologies) for single fibres selected from 15 woolen and 15 polyamide fabrics, were studied. The results indicated that at the same concentration of dye, the dyes' affinity is higher for polyamide fibres than for wool. Thus, the conduction of the examination of single wool fibres in the visible and in the UV-A range can be recommended, and in the case of analysing fibres with similar microscopic colour, the chemometric treatment seems to be an effective way of discrimination.